diff options
Diffstat (limited to 'drivers/soc/qcom/qpnp-pbs.c')
| -rw-r--r-- | drivers/soc/qcom/qpnp-pbs.c | 361 |
1 files changed, 361 insertions, 0 deletions
diff --git a/drivers/soc/qcom/qpnp-pbs.c b/drivers/soc/qcom/qpnp-pbs.c new file mode 100644 index 000000000000..287c8a25b391 --- /dev/null +++ b/drivers/soc/qcom/qpnp-pbs.c @@ -0,0 +1,361 @@ +/* Copyright (c) 2017, The Linux Foundation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#define pr_fmt(fmt) "PBS: %s: " fmt, __func__ + +#include <linux/delay.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/spmi.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/err.h> +#include <linux/of.h> +#include <linux/qpnp/qpnp-pbs.h> + +#define QPNP_PBS_DEV_NAME "qcom,qpnp-pbs" + +#define PBS_CLIENT_TRIG_CTL 0x42 +#define PBS_CLIENT_SW_TRIG_BIT BIT(7) +#define PBS_CLIENT_SCRATCH1 0x50 +#define PBS_CLIENT_SCRATCH2 0x51 + +static LIST_HEAD(pbs_dev_list); +static DEFINE_MUTEX(pbs_list_lock); + +struct qpnp_pbs { + struct platform_device *pdev; + struct device *dev; + struct device_node *dev_node; + struct regmap *regmap; + struct mutex pbs_lock; + struct list_head link; + + u32 base; +}; + +static int qpnp_pbs_read(struct qpnp_pbs *pbs, u32 address, + u8 *val, int count) +{ + int rc = 0; + struct platform_device *pdev = pbs->pdev; + + rc = regmap_bulk_read(pbs->regmap, address, val, count); + if (rc) + pr_err("Failed to read address=0x%02x sid=0x%02x rc=%d\n", + address, to_spmi_device(pdev->dev.parent)->usid, rc); + + return rc; +} + +static int qpnp_pbs_write(struct qpnp_pbs *pbs, u16 address, + u8 *val, int count) +{ + int rc = 0; + struct platform_device *pdev = pbs->pdev; + + rc = regmap_bulk_write(pbs->regmap, address, val, count); + if (rc < 0) + pr_err("Failed to write address =0x%02x sid=0x%02x rc=%d\n", + address, to_spmi_device(pdev->dev.parent)->usid, rc); + else + pr_debug("Wrote 0x%02X to addr 0x%04x\n", *val, address); + + return rc; +} + +static int qpnp_pbs_masked_write(struct qpnp_pbs *pbs, u16 address, + u8 mask, u8 val) +{ + int rc; + + rc = regmap_update_bits(pbs->regmap, address, mask, val); + if (rc < 0) + pr_err("Failed to write address 0x%04X, rc = %d\n", + address, rc); + else + pr_debug("Wrote 0x%02X to addr 0x%04X\n", + val, address); + + return rc; +} + +static struct qpnp_pbs *get_pbs_client_node(struct device_node *dev_node) +{ + struct qpnp_pbs *pbs; + + mutex_lock(&pbs_list_lock); + list_for_each_entry(pbs, &pbs_dev_list, link) { + if (dev_node == pbs->dev_node) { + mutex_unlock(&pbs_list_lock); + return pbs; + } + } + + mutex_unlock(&pbs_list_lock); + return ERR_PTR(-EINVAL); +} + +static int qpnp_pbs_wait_for_ack(struct qpnp_pbs *pbs, u8 bit_pos) +{ + int rc = 0; + u16 retries = 2000, dly = 1000; + u8 val; + + while (retries--) { + rc = qpnp_pbs_read(pbs, pbs->base + + PBS_CLIENT_SCRATCH2, &val, 1); + if (rc < 0) { + pr_err("Failed to read register %x rc = %d\n", + PBS_CLIENT_SCRATCH2, rc); + return rc; + } + + if (val == 0xFF) { + /* PBS error - clear SCRATCH2 register */ + rc = qpnp_pbs_write(pbs, pbs->base + + PBS_CLIENT_SCRATCH2, 0, 1); + if (rc < 0) { + pr_err("Failed to clear register %x rc=%d\n", + PBS_CLIENT_SCRATCH2, rc); + return rc; + } + + pr_err("NACK from PBS for bit %d\n", bit_pos); + return -EINVAL; + } + + if (val & BIT(bit_pos)) { + pr_debug("PBS sequence for bit %d executed!\n", + bit_pos); + break; + } + + usleep_range(dly, dly + 100); + } + + if (!retries) { + pr_err("Timeout for PBS ACK/NACK for bit %d\n", bit_pos); + return -ETIMEDOUT; + } + + return 0; +} + +/** + * qpnp_pbs_trigger_event - Trigger the PBS RAM sequence + * + * Returns = 0 If the PBS RAM sequence executed successfully. + * + * Returns < 0 for errors. + * + * This function is used to trigger the PBS RAM sequence to be + * executed by the client driver. + * + * The PBS trigger sequence involves + * 1. setting the PBS sequence bit in PBS_CLIENT_SCRATCH1 + * 2. Initiating the SW PBS trigger + * 3. Checking the equivalent bit in PBS_CLIENT_SCRATCH2 for the + * completion of the sequence. + * 4. If PBS_CLIENT_SCRATCH2 == 0xFF, the PBS sequence failed to execute + */ +int qpnp_pbs_trigger_event(struct device_node *dev_node, u8 bitmap) +{ + struct qpnp_pbs *pbs; + int rc = 0; + u16 bit_pos = 0; + u8 val, mask = 0; + + if (!dev_node) + return -EINVAL; + + if (!bitmap) { + pr_err("Invalid bitmap passed by client\n"); + return -EINVAL; + } + + pbs = get_pbs_client_node(dev_node); + if (IS_ERR_OR_NULL(pbs)) { + pr_err("Unable to find the PBS dev_node\n"); + return -EINVAL; + } + + mutex_lock(&pbs->pbs_lock); + rc = qpnp_pbs_read(pbs, pbs->base + PBS_CLIENT_SCRATCH2, &val, 1); + if (rc < 0) { + pr_err("read register %x failed rc = %d\n", + PBS_CLIENT_SCRATCH2, rc); + goto out; + } + + if (val == 0xFF) { + /* PBS error - clear SCRATCH2 register */ + rc = qpnp_pbs_write(pbs, pbs->base + PBS_CLIENT_SCRATCH2, 0, 1); + if (rc < 0) { + pr_err("Failed to clear register %x rc=%d\n", + PBS_CLIENT_SCRATCH2, rc); + goto out; + } + } + + for (bit_pos = 0; bit_pos < 8; bit_pos++) { + if (bitmap & BIT(bit_pos)) { + /* + * Clear the PBS sequence bit position in + * PBS_CLIENT_SCRATCH2 mask register. + */ + rc = qpnp_pbs_masked_write(pbs, pbs->base + + PBS_CLIENT_SCRATCH2, BIT(bit_pos), 0); + if (rc < 0) { + pr_err("Failed to clear %x reg bit rc=%d\n", + PBS_CLIENT_SCRATCH2, rc); + goto error; + } + + /* + * Set the PBS sequence bit position in + * PBS_CLIENT_SCRATCH1 register. + */ + val = mask = BIT(bit_pos); + rc = qpnp_pbs_masked_write(pbs, pbs->base + + PBS_CLIENT_SCRATCH1, mask, val); + if (rc < 0) { + pr_err("Failed to set %x reg bit rc=%d\n", + PBS_CLIENT_SCRATCH1, rc); + goto error; + } + + /* Initiate the SW trigger */ + val = mask = PBS_CLIENT_SW_TRIG_BIT; + rc = qpnp_pbs_masked_write(pbs, pbs->base + + PBS_CLIENT_TRIG_CTL, mask, val); + if (rc < 0) { + pr_err("Failed to write register %x rc=%d\n", + PBS_CLIENT_TRIG_CTL, rc); + goto error; + } + + rc = qpnp_pbs_wait_for_ack(pbs, bit_pos); + if (rc < 0) { + pr_err("Error during wait_for_ack\n"); + goto error; + } + + /* + * Clear the PBS sequence bit position in + * PBS_CLIENT_SCRATCH1 register. + */ + rc = qpnp_pbs_masked_write(pbs, pbs->base + + PBS_CLIENT_SCRATCH1, BIT(bit_pos), 0); + if (rc < 0) { + pr_err("Failed to clear %x reg bit rc=%d\n", + PBS_CLIENT_SCRATCH1, rc); + goto error; + } + + /* + * Clear the PBS sequence bit position in + * PBS_CLIENT_SCRATCH2 mask register. + */ + rc = qpnp_pbs_masked_write(pbs, pbs->base + + PBS_CLIENT_SCRATCH2, BIT(bit_pos), 0); + if (rc < 0) { + pr_err("Failed to clear %x reg bit rc=%d\n", + PBS_CLIENT_SCRATCH2, rc); + goto error; + } + + } + } + +error: + /* Clear all the requested bitmap */ + rc = qpnp_pbs_masked_write(pbs, pbs->base + PBS_CLIENT_SCRATCH1, + bitmap, 0); + if (rc < 0) + pr_err("Failed to clear %x reg bit rc=%d\n", + PBS_CLIENT_SCRATCH1, rc); +out: + mutex_unlock(&pbs->pbs_lock); + + return rc; +} +EXPORT_SYMBOL(qpnp_pbs_trigger_event); + +static int qpnp_pbs_probe(struct platform_device *pdev) +{ + int rc = 0; + u32 val = 0; + struct qpnp_pbs *pbs; + + pbs = devm_kzalloc(&pdev->dev, sizeof(*pbs), GFP_KERNEL); + if (!pbs) + return -ENOMEM; + + pbs->pdev = pdev; + pbs->dev = &pdev->dev; + pbs->dev_node = pdev->dev.of_node; + pbs->regmap = dev_get_regmap(pdev->dev.parent, NULL); + if (!pbs->regmap) { + dev_err(&pdev->dev, "Couldn't get parent's regmap\n"); + return -EINVAL; + } + + rc = of_property_read_u32(pdev->dev.of_node, "reg", &val); + if (rc < 0) { + dev_err(&pdev->dev, + "Couldn't find reg in node = %s rc = %d\n", + pdev->dev.of_node->full_name, rc); + return rc; + } + + pbs->base = val; + mutex_init(&pbs->pbs_lock); + + dev_set_drvdata(&pdev->dev, pbs); + + mutex_lock(&pbs_list_lock); + list_add(&pbs->link, &pbs_dev_list); + mutex_unlock(&pbs_list_lock); + + return 0; +} + +static const struct of_device_id qpnp_pbs_match_table[] = { + { .compatible = QPNP_PBS_DEV_NAME }, + {} +}; + +static struct platform_driver qpnp_pbs_driver = { + .driver = { + .name = QPNP_PBS_DEV_NAME, + .owner = THIS_MODULE, + .of_match_table = qpnp_pbs_match_table, + }, + .probe = qpnp_pbs_probe, +}; + +static int __init qpnp_pbs_init(void) +{ + return platform_driver_register(&qpnp_pbs_driver); +} +arch_initcall(qpnp_pbs_init); + +static void __exit qpnp_pbs_exit(void) +{ + return platform_driver_unregister(&qpnp_pbs_driver); +} +module_exit(qpnp_pbs_exit); + +MODULE_DESCRIPTION("QPNP PBS DRIVER"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:" QPNP_PBS_DEV_NAME); |